LCOS动态相位光栅的衍射特性分析

Analysis on the Diffraction Characteristics of LCOS Dynamic Phase Grating

LCOS(硅基液晶)芯片的相邻像素之间存在电场边缘效应,产生的寄生光栅效应劣化了WSS(波长选择开关)端口之间的串扰水平。文章建立了简化的2f光学模型,并基于傅里叶光学方法仿真分析了LCOS芯片中电场边缘效应对WSS性能指标的影响。结果表明,光束经LCOS光栅的衍射角越大,则WSS输出端口间的串扰越大;通过减小WSS端口间距或增大透镜焦距可以减小串扰,继而增大WSS的端口数。该研究结果对WSS的参数设计和优化具有重要的参考价值。

The electrical fringing field effect between neighboring pixels of the LCOS chip will result in a parasitic grating and the crosstalk among the ports of the WSS(Wavelength Selective Switch)module.A simplified 2foptical model was established and the relationship between the electrical fringing field effect and the performances of the WSS module was analyzed based on Fourier optics.The result shows that,with the increase of the diffraction angle of the LCOS grating,the crosstalk among the outputs of the WSS module increase.Reducing the space between the outputs or increasing the focal length of the lens can reduce the crosstalk,resulting in the more the number of outputs in the WSS module.The results presented in this paper are important for the parameter design and optimization of WSS module.